I was hoping someone could help me out with an Pre cat O2 sensor issue im having. Dealership says my PreCat O2 sensors are damaged and need to be replaced. Quoting me $1200 for the job. I read that that Bosche O2 sensors are ~$130 online. So I am guessing the $1000 is for Labor?! Should I just go ahead and do this job myself? I heard the job is a pain.

Dealer also switched out my battery and bill is now $700, so they will be adding $1200+ to the bill with those o2s.